I'm 8 months into a 24 month orange Contract where I have a iPhone 4s, just wondered if I would be able to buy a iPhone 5 at a lower price from orange?

You'd need to either

1. Buy out your contract
2. Take out an additional contract
3. Buy it on pay as you go or sim free

O2 ran a scheme when the iPhone 4 came out where people could upgrade early by paying £20 per month remaining as an upgrade charge although no other network has ever run anything similar and a little bit of maths revealed this wasn't as good an offer as it seemed when you factored in the tariff downgrade policy at the time permitted people to eventually reach £10 per month on their tariff